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Road drainage culverts have been designed to accommodate the ten yeaz 24 hour precipitation <br />event. Descriptions of culvert designs, placement, and protection for culvert inlets and outlets have <br />been discussed in Appendix 5-2. <br />The haul road is maintained with graders and other equipment necessary to provide smooth, <br />adequate surface for the hauling of coal from the pit area to the staging azea. Also, an existing light <br />duty access road is used at the mine. The subject road has been identified on the applicable maps. <br />The existing road will be maintained and upgraded as necessary for mine access. It is expected that <br />the existing road will be graded and graveled with a 2" x 0" gravel for light duty vehicles. No 50- <br />ton coal haulers will use this road. <br />The haul road will remain as a permanent access to the property after mining has been completed. <br />A letter from the landowner has been enclosed in Appendix 5-1 authorizing the haul road to remain <br />after mining and reclamation for the post mining land use. The access roads will also remain as a <br />part of the post mining land use as described in Appendix 5-1. <br />2.05.3(4) Ponds, Impoundments and Diversions <br />The sediment control system for the mine is being substantially modified for the reclamation only <br />permit. The sediment control system will employ structures to contain runoff from a 10-year, 24- <br />hour precipitation event. The sediment control system will include a new collection ditch from the <br />Permanently Reclaimed Spoils Area to Sediment Pond # 2, Sediment Pond # 2, three detention <br />sumps below the North Pit and North Pit outslope, and a detention sump below the reclaimed <br />Topsoil Stockpile # 2. Further, Carbon Junction Canyon will be reconstructed to flow through a <br />new permanent diversion. <br />Surface water control within the permit area employs a series of collection ditches and channels, <br />berms, and two sediment ponds to direct and control sediment laden surface waters. In general, <br />surface water runoff from the South Pit and area to the east and south, is conveyed via the East <br />Collection Channel to Sediment Pond No. I, which has been adequately designed and constructed <br />to contain the design storm event flow and runoff. The East Collection Channel above the <br />Permanently Reclaimed Spoils Area is the original Carbon Junction Canyon drainage channel. <br />Runoff from the joint use area is conveyed via the East Collection Ditch azoand the east end of the <br />facilities area to Sediment Pond No. 1. Surface water drainage from Topsoil Stockpile No. 2, the <br />permanently reclaimed spoils azea, and the haul road is conveyed via the West Collection Ditch to <br />Sediment Pond No. 2. Sediment Pond No. 2 was originally designed and constructed to handle <br />flows from a larger area, and as such is currently oversized. Within the next few years, as <br />reclamation of the permanently reclaimed spoils area is completed, Sediment Pond No. 2 will <br />become unneeded and ultimately removed. Designs for all elements of the sediment control plan <br />are contained in Appendices 5-2, 5-9, 5-10. and Map 5-10. <br />TR09, TRl 1, TR12 (v1.0) 5-4 Revised 3/9S, 8/02, 9/03 <br />